Population density, distribution and biomass of macrobenthic fauna in Chabahar Bay were investigated from May 1995 to March 1996 on a bimonthly basis. The most abundant groups were Amphipods (21%), Polychaetes (19%), Gastropods (15.7%) and Bivalves (10.6%). Maximum (13000 individuals/m2) and minimum (4600 individuals/m2) were observed in May and July respectively. The changes in density were influenced by monsoon season of the Indian Ocean. Spatial and temporal variations in biomass were recorded for all groups separately. The lowest biomass was observed during monsoon period (July-September) with a mean of 51.5 g dry wt/m2 and the highest in permonsoon period (March-May) with an average of 164.8 g dry wt/m2. The results are discussed in terms of understanding secondary production of Chabahar Bay.